AU7922598A

AU7922598A - Turbojet thrust reverser with doors forming scoops associated with a movable deflector

Info

Publication number: AU7922598A
Application number: AU79225/98A
Authority: AU
Inventors: Patrick Gonidec; Jean Fabrice Marcel Portal; Vincent Joseph Rodolphe Studer; Guy Bernard Vauchel
Original assignee: Hispano Suiza Aerostructures; Hispano Suiza SA
Current assignee: Safran Nacelles SAS
Priority date: 1997-06-05
Filing date: 1998-06-04
Publication date: 1998-12-21
Anticipated expiration: 2018-06-04
Also published as: FR2764341A1; CA2239465A1; JPH10339212A; US6065285A; FR2764341B1; AU724455B2; EP0882883A1; RU2162538C2; WO1998055755A1

Description

TURBOJET THRUST REVERSER WITH DOORS FORMING SCOOPS ASSOCIATED WITH A MOVABLE DEFLECTOR The present invention relates to a double flow turbojet thrust reverser. The turbojet is 5 provided with a conduit in the rear of the blower whose purpose is to direct the secondary flow, also called the cold flow; this conduit comprises an internal wall which surrounds the structure of the engine itself in the rear of the blower, and an external wall whose upstream part extends the crankcase which surrounds the blower. This external wall can simultaneously direct both the secondary flow and the primary 10 flow in its downstream part, and this after the ejection of the primary flow, also called the hot flow, in the case of a nacelle with mixed flows or confluent flows for example, but in other cases, the external wall directs only the secondary flow in the case of nacelles called separate flow nacelles. 15 A wall can also careen the exterior of the engine, namely the exterior of the housing that surrounds the blower and the exterior of the external wall of the conduit described above, to minimise the drag of the propulsion unit. This is particularly the case of propulsion units joined onto the exterior of the aircraft, particularly when the propulsion units are attached under the wings or in the rear of the fuselage. 20 The French patent application 96.09705 describes an embodiment, shown in Figure 1 of the accompanying drawings, of a thrust reverser with doors forming scoops associated to a double flow turbojet. 25 The reversing device consists of a movable unit and a fixed structure. The movable unit consists of hollow doors 3 forming a movable part 2 and constituting, in the direct jet position, a portion of the external cowling of the nacelle. The fixed structure consists of an upstream part 6 upstream from the doors and a downstream part 7 downstream from the doors 3 and beams which link the upstream part 6 to the 2 downstream part 7, the fixed structure itself also forming a portion of the exterior cowling. The doors 3 are mounted on a circumference of the external cowling and are pivotably 5 mounted in a zone downstream from their lateral walls on the beams linking the downstream part 7 to the upstream part 6 of the external cowling situated on both sides of these doors; these lateral walls link the external part or external panel 4 of the doors 3, which forms part of the external wall of the nacelle, to the internal part 5 of the doors 3 which forms part of the external wall of the conduit. 10 The upstream part 6 of fixed structure comprises a front frame 8 which can serve as a support to the means for controlling the movements of the doors 3, consisting of, for example, thrusters. These means for controlling the movements of the doors 3 can also be situated at other places around the door 3, for example, downstream from the latter. 15 In this case it is the downstream structure 7 with fixed structure that can support the control mechanisms. In the activated position, the doors 3 rock in such a manner that the part of the doors situated upstream from the pivots 9 blocks more or less completely the conduit while 20 clearing a passage in the external cowling so as to allow the secondary flow respectively 13 and 14 to be directed in a direction which is centrifugal in relation to the axis of the conduit on the one hand in the conduit or tuyere 10 formed by the structure of the door 3 and on the other hand, between the deviation edge and the exterior of the external structure 4 of the door 3. The downstream part of the doors 25 comes to the vicinity of the exterior of the external cowling. The pivoting angle of the doors is adjusted so as to let the flow pass and to considerably reduce or even to suppress the thrust of this flow, and to generate a counter thrust by producing a flow component deviated upstream. 30 Due to the struggle of the door to free itself from the constraints of aerodynamic R 41 ensioning of the passing of the flow into the free passages from the upstream part Pr or 3 of the door and the positioning of the door in a reversed jet, the type of thrust reverser described above has a prominent shape 12 outside and downstream from the frame 8. A more or less marked zone of dead water 11, as usually encountered in all traditional concepts involving doors in this zone, reduces the section of the passage of 5 the flowl4 while minimising the reversion angle of the flow 14 towards the front of the nacelle. Indeed this dead zone 11 forms an aerodynamic plug which reduces the cross section of the reversion well. The fact that the cross section of the passage of the reversion flow is restrained 10 implies a reduction of aerodynamic performance. The reversion flow 14 being in an awkward position to fully proceed to the front of the nacelle, the latter marks the ramp created by the exterior of the external panel of the door and meets the flow 13b emerging from the interior 10 of the door. In its turn, the flow 14 minimises the direction taken by the flow 13b toward the front of the nacelle by merging with it. 15 One of the objectives of the invention is to obtain an increase in the aerodynamic performance of scoop doors, especially during in an operation in a thrust reversal of the reverser without incurring the disadvantages of the previously known solutions. According to the invention, the objectives are achieved by a turbojet thrust reverser 20 with doors forming scoops of the aforementioned type, characterised in that the door is associated with a movable deflector which is situated, when the door is opened, above the surface of the exterior of the external panel of the door so as to limit or avoid all interference between the exhaust flow of the door and the flow deviated to the exterior of the door. Z5 The other characteristics and advantages of the invention will be better understood by reading the following description of the embodiments of the invention in reference to the accompanying drawings in which: 41 D

TC'

4 - Figure 1 is a schematic half-view of a longitudinal section, sectioned by a plane passing through the axis of rotation of an associated turbojet, of a thrust reverser with pivoting scoop doors in the open position, of a known type which has previously been the subject of a description; 5 - Figure 2 is a view, similar to that shown in Figure 1, of a thrust reverser with scoop doors in the closed position according to an embodiment of the invention; - Figure 3 shows the embodiment shown in Figure 2 in the reversed jet mode; 10 - Figures 4 and 5 show in perspective the concept shown in Figures 2 and 3; - Figure 6 is a view similar to that shown in Figure 1 of a thrust reverser with scoop doors in the closed position according to another embodiment of the invention; 15 - Figure 7 shows the embodiment shown in Figure 6 in the reversed jet mode; - Figure 8 shows in perspective the concept defined according to Figures 6 and 7 in the reversed jet mode; 20 - Figure 9 is a view similar to that shown in Figure 1 of a thrust reverser with scoop doors in the closed position according to another embodiment of the invention; - Figure 10 shows the embodiment shown in Figure 9 in the reversed jet mode; Z5 - Figures 11 and 12 show in perspective the concept defined according to Figures 9 and 10. T O .44 7 r'>7- 5 According to an embodiment shown in Figures 2, 3, 4 and 5, a door 3 with a tuyere articulated around an axis of rotation 9 supported by the lateral beams of the fixed structure 6 of a double flow turbojet thrust reverser, drives and supports, by means of at least two lateral connecting rods 20 and 21 articulated at 22 and 23 on the door 3, a 5 movable deflector 24 at the linking points 25 and 26, respectively. In a direct jet, the exterior of the deflector 24 forms part of the external nacelle. The internal surface 27 of the movable deflector 24 has a shape adapted to ensure the performance in a reversed jet sought by the person skilled in the art and can be 10 associated with other aerodynamic elements, for example, a vane carried by the deflector itself. The length of the movable deflector is not limited, either upstream or downstream; it depends on the arrangements made by the person skilled in the art concerning its positioning in space and in relation to the surroundings. In addition, the upstream and downstream trimming of the movable deflector can have all the 15 geometric dispositions necessary to the desired performance. The positioning of the movable deflector in a reversed jet is adjusted to optimally assist the guidance of a portion of the flow in a chosen direction. The upstream edge 28 of the movable deflector 24 can cover a portion of the frame 20 without interfering with the fixed structure during the operation of the door. This disposition makes it possible to reduce at least partially the prominent shape 12. In order to increase the rate of the flow 13 passing through the conduit forming a tuyere 10 of the door in a reversed jet, at least one vane 52 can be placed in the conduit 10 of the door under the movable deflector 24 in a direct jet position. This vane 52, exposed 25 in the reversed jet position, directs a portion of the flow in the direction desired by the person skilled in the art either toward the interior of the door or toward the exterior in the rear of the movable deflector for example; moreover, it can help the closure in a ST <sed jet.

6 Advantageously, an additional guiding connecting rod 29 fastened to the fixed structure 6 by the pivot 30 is linked to the set consisting of the movable deflector 24 and the connecting rods 20, 21 at a certain point, making it possible to obtain the kinematics desired by the person skilled in the art. In the example shown the point is 5 confounded with the pivot 26 of the connecting rod 21. The restrained disposition makes the upstream edge of the movable deflector 24 pivot in a direction which is centripetal in relation to the axis of the nacelle. So disposed, the deflector can direct a portion of the flow 14 toward the exterior of the nacelle in a direction leading to a better aerodynamic performance; moreover, less flow interferes with that emerging 10 from the door 3, thereby improving the efficiency of the latter. The upstream edge 28 of the movable deflector 24 can similarly come into contact with the external panel 4 to prevent the flow 14 from passing between the two elements. By modifying the disposition and the parameters of the rodding system, any person 15 skilled in the art can perform an upstream rotation of the movable deflector 24 in a centripetal direction in relation to the axis of the nacelle and position it in the vicinity of the external panel 4 of the door 3. Moreover, it is possible to render it tight with said external panel to make an obstacle to the flow 14 and to redirect it more efficiently toward the front of the exterior of the nacelle. 20 The movable deflector 24 can be integrally situated in the upstream of the structure of the door as shown in Figures 2 to 5. It can ride on a portion of the external structure of the door or can be positioned in an intermediate zone between the upstream and the downstream of the structure of the external panel 4. In this last configuration, 5 advantageously, the movable deflector 24 can be directly articulated on the external structure 4 of the door 3 upstream or downstream depending on the case. Moreover, the vanes 52 can be placed inside the conduit 10 of the structure of the door in the ST 1W surroundings created by the release of the movable deflector 24 to make it V - 0 7 possible to optimally direct a portion of the flow passing through the internal door conduit 10. In the example shown in Figure 2, the pivot 30 linking the movable deflector 24 to the 5 fixed structure 6 is situated in the upstream part of said movable deflector. This disposition allows the internal surface 27 to contribute to the retention of the door during the starting phase of the operation or to assist the re-closure, thereby reducing the pressure seen by the thrustor in this phase of operation. 10 Placing the movable deflector 24 upstream from the door structure 3 can lead to a better evacuation of air during the start of the opening operation by immediately freeing a section toward the exterior of the nacelle. Figures 6 to 8 show another embodiment of the invention. In the direct jet position, a 15 movable deflector 31 is disposed under the fixed visor 40 of the rear ferrule. At least two connecting rods 32 and 33, linked to the door 3 and articulated at points 34 and 35, respectively, guide and direct the movable deflector 31 at pivot points 36 and 37. In this example, the movable deflector is driven by a roller 38 adapted to the connecting rod 33, which slides in a ramp 39 integrated with the fixed structure of the 20 reverser when the door 3 moves. This guiding principle has the advantage, compared with the system having a third connecting rod, that the movement of the movable deflector 31 is guided by an adapted definition. In order to avoid interference at the start of the operation of opening the door 3, for example, between the movable deflector 31 and the visor 40, it 5 is possible to define a non-active zone in the beginning of the ramp 39. At the end of the opening operation, the movable deflector 31 is situated in the ,T Rwnstream part of the external panel 4 of the door 3. The kinematics by rodding -v7 8 creating, in this disposition, a movement of re-closure of the movable deflector on the surface of the door, tightness can be achieved in the downstream of the movable deflector 31. A zone of excess pressure is created in the upstream of the movable deflector 31 and a low pressure zone in the rear side of this element. This disposition 5 makes it possible to improve the aerodynamic performance of the concept. Moreover, the movable deflector 31 can contain at least one associated opening depending on the need for at least one louvre 41 for directing the reversed flow passing through said opening, similar in spirit to the disposition provided by EP 0 301 955. 10 Figures 9 to 12 propose another embodiment of the invention. In this version, at least two connecting rods 43 and 44, linked to the door 3 and articulated at points 45 and 46, respectively, guide and direct the movable deflector 41 at pivot points 47 and 48. A connecting rod 49 linked and articulated to the fixed structure at a pivot point 50 works the movable deflector 42 through the movement of the door 3. Its point of 15 articulation on the movable deflector is shown at point 48 on the figure, but can be at any other place of the movable set considered useful by the person skilled in the art. The advantage of this disposition , according to the definition of restrained streamlines, is to make it possible to increase the outlet section 53 and to increase the 20 number of vanes 51, which consequently improves the aerodynamic efficiency of the flow 13 passing through the channel 10 of the door 3. Naturally, depending on the needs, the movable deflector 42 can be arranged in consequence; for example, the height can be increased to enhance the barrier effect, and the surface forming a portion of the external nacelle can be extended upstream to 5 increase the outlet section 53 of the door 3. The movable deflectors 24, 31 and 42 can be worked independently of the door 3 by any engine system known by the person skilled in the art and can be guided either 9 simultaneously, sequentially, in advance or in delay in relation to the opening of the door. Consequently, it is technically possible to drive the door 3 by the bias of the movable 5 deflectors according to the arrangement previously described. T /,

Claims

1. A double flow turbojet thrust reverser comprising pivoting hollow doors (3), comprising in the closed position, in an operation in a direct jet, a portion of the external cowling of the nacelle and after pivoting under the action of a means for 5 controlling movements, the upstream door edge penetrating into the flow, the doors (3) constituting deviation obstacles to the flow by freeing a passage on the external cowling, in an operation in a thrust reversal, at least a portion of the deviated flow navigating the internal conduit (10) or tuyere of the door (3), characterised in that said door (3) is associated with a movable deflector (24;3 1; 42) which is situated, when the 10 door (3) is opened, above the surface of the exterior of the external panel (4) of the door (3) so as to limit or avoid all interference between the exhaust flow of the door (3) and the flow deviated to the exterior of the door (3).

2. A double flow turbojet thrust reverser according to claim 1, characterised in 15 that said movable deflector (24), disposed in a direct jet upstream from the external panel (4) of the door (3), forms part of the external surface of the nacelle and is supported and driven by the door (3) by means of at least two lateral connecting rods (20, 21) articulated at their ends. 20

3. A double flow turbojet thrust reverser according to claim 2, characterised in that said movable deflector (24) is linked by an additional connecting rod (29) to a fixed pivot (30) fastened to the fixed structure (6) of the reverser.

4. A double flow turbojet thrust reverser according to any one of the claims 1 to 3, 25 characterised in that when the door (3) is opened, the upstream edge of the movable deflector (24) rocks in a centripetal direction in relation to the longitudinal axis of the nacelle. 1-44 4' 11

5. A double flow turbojet thrust reverser according to any one of the claims 1 to 3, characterised in that when the door (3) is opened, the downstream edge of the movable deflector (24) rocks in a centripetal direction in relation to the longitudinal axis of the nacelle. 5

6. A double flow turbojet thrust reverser according to claim 1, characterised in that the movable deflector (24) is placed in a direct jet in an intermediate zone between the upstream and the downstream of the external panel (4) of the door (3). 10

7. A double flow turbojet thrust reverser according to claim 1, characterised in that the movable deflector (31; 42) is disposed in a direct jet downstream from the external panel (4) of the door (3).

8. A double flow turbojet thrust reverser according to claim 7, characterised in 15 that the movable deflector (31) is disposed in a direct jet under the fixed upstream visor (40) of the fixed rear ferrule (7) of the reverser.

9. A double flow turbojet thrust reverser according to claim 8, characterised in that the downstream zone of contact between the movable deflector (31) and the 20 external door panel (4) is tight, when the door (3) is opened and said movable deflector (31) comprises at least one louvre opening (41).

10. A double flow turbojet thrust reverser according to claim 7, characterised in that the movable deflector (42) is disposed in a direct jet between the downstream edge 25 of the external panel (4) of the door (3) and the upstream edge of the fixed upstream visor (40) of the fixed rear ferrule (7) of the reverser. 12

11. A turbojet thrust reverser according to any one of the claims 7 to 10, characterised in that the movable deflector (31) is driven by the door (3) by means of at least two connecting rods (32, 33) articulated at their ends, one (33) of the connecting rods carrying a roller (38) which slides in a guiding ramp (39) integrated with the fixed 5 structure of the reverser, the movable deflector (31) being situated, when the door (3) is opened, on the downstream external edge of the external panel of the door (3), to the edge of the outlet of the flow navigating the internal conduit (10) of the door (3).

12. A turbojet thrust reverser according to any one of the claims 7 to 10, 10 characterised in that the movable deflector (41) is supported and driven by the door (3) by means of at least two connecting rods (32, 33) articulated at their ends, an additional connecting rod (49) linking the movable deflector (42) to a fixed pivot (50) fastened to the fixed structure of the reverser. 15

13. A double flow turbojet thrust reverser according to claim 1, characterised in that the movable deflector (24; 31; 42) is associated with movement controlling means which are independent of the door (3).

14. A double flow turbojet thrust reverser according to claim 1, characterised in 20 that the movements of the door (3) are obtained thanks to the movement controlling means of the movable deflector (24). -1 RA4X 1U